The communications industry is rapidly changing to adjust to emerging technologies and ever increasing customer demand. This customer demand for new applications and increased performance of existing applications is driving communications network and system providers to employ networks and systems having greater speed and capacity (e.g., greater bandwidth). In trying to achieve these goals, a common approach taken by many communications providers is to use packet switching technology. Note, nothing described or referenced in this document is admitted as prior art to this application unless explicitly so stated.
Multiprotocol Label Switching (MPLS) is a switching technology which uses a short fixed length values known “labels” to switch packets through a network. A label identifies to the receiving switching device a value from it can readily identify how to forward the packet upon receipt. A label is chosen arbitrarily (e.g., such by retrieving any unused label from a pool of currently unused labels) beforehand by the receiving packet switching device, which informs its adjacent packet switching devices on which label to use for sending packets belonging to a Forwarding Equivalence Class (FEC). In MPLS, the assignment of a particular packet to a particular FEC is done just once, as the packet enters the network. When a packet is forwarded to its next hop, the label is sent along with it. At subsequent hops, there is no further analysis of the packet's network layer header. Rather, the label is used as an index into a table which specifies the next hop, and a new label. The old label is replaced with the new label, and the packet is forwarded to its next hop.